In general, as supports for photographic light-sensitive materials, synthetic polymeric substances such as cellulose ester, polystyrene, polycarbonate and polyethylene terephthalate, glass, paper, and poly-.alpha.-olefin coated paper are used. These supports are coated directly or through a subbing layer with a photographic silver halide emulsion layer. In many light-sensitive materials, a surface protective layer is coated on the photographic emulsion layer in order to prevent sticking of the light-sensitive material or among light-sensitive materials, and to prevent scratches during processing. In addition, coating layers composed of gelatin or other hydrophilic colloids, or vinyl polymer latex containing various additives such as dyes, antistatic agents, hardeners, color-forming couplers, and halation-preventing agents, e.g., an antihalation layer, an intermediate layer, a filter layer, and an antistatic layer are typically coated.
Thus, the usual photographic light-sensitive materials are composed of many hydrophilic organic colloid layers. In producing such photographic light-sensitive materials, therefore, it is required that coating solutions are coated uniformly at a high speed without causing troubles such as repellency and uneven coating to form thin organic colloid layers.
Furthermore, in the production of photographic light-sensitive materials, multilayer coating is often employed in which photographic emulsions and coating solutions containing hydrophilic organic colloid, e.g., gelatin, are coated at the same time. For example, photographic emulsion layers having different light-sensitive regions are continuously coated to prepare a color photographic light-sensitive material. When gelatin or other organic colloid solutions are coated on organic colloid (e.g., gelatin) layers, greater difficulty is encountered in obtaining the necessary coating characteristics compared with the case wherein a gelatin colloid solution is coated directly on a support. This difficulty arises particularly in the case of the underlying coated layers being present in the state that they are just after coating and being cooled.
In the case of color photographic light-sensitive materials, many water-sparingly-soluble additives such as color couplers, ultraviolet ray absorbing agents, and fluorescent whitening agents are dissolved in high boiling point organic solvents such as phthalate-based compounds and phosphate-based compounds, dispersed (or emulsified) in a solution of hydrophilic organic colloid, particularly gelatin in the presence of a surface active agent, and incorporated into a hydrophilic organic colloid layer. In this case, when a large amount of surface active agent is used as the emulsifying agent, it becomes difficult to coat additional other hydrophilic organic colloid layers on the hydrophilic organic colloid layer, whereas when the amount of the emulsifying agent being added is small, the photographic properties of the photographic light-sensitive material after the coating thereof become instable.
Various surface active agents have heretofore been used as coating aids for various coating solutions for use in the preparation of photographic light-sensitive materials, as emulsifying agents, or as additives to improve the surface characteristics of a photographic surface layer. In particular, saponin has been widely used as a coating aid in the photographic industry. The saponin, however, has disadvantages in that it is responsible for easy formation of foams, the quality varies markedly since it is a natural product, and the characteristics as a coating aid are poor. With other synthetic surface active agents, the action thereof on various coating solutions, or on the coating and surface characteristics of the photographic coating layer varies depending on the type of the surface active agent. This imposes limitations on the range of applications in which they can be used. Suitable surface active agents, therefore, are selected and utilized according to the particular individual application itended.
Examples of such surface active agents are described, for example, in U.S. Pat. Nos. 2,240,469, 2,240,492, 2,240,475, 3,026,202, 3,169,879, 3,201,252, 3,165,409, 3,507,660, 3,539,352, 3,516,835, 3,619,119, 3,824,102, and 2,992,108, and Japanese Patent Application (OPI) Nos. 46733/74 and 3233/76 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application"). These surface active agents, however, are not completely satisfactory, in that they deteriorate the photographic characteristics, particularly the physical properties of a film, at high temperatures and humidities, and in that the stability of the surface active agent per se is poor and high speed coating properties are insufficient.